#operationList{
    display: flex;
    flex-wrap: wrap;
    width: 15%;
    height: 100%;
    align-content: center;
}
.operation {
    width: 100%;
    display: flex;
    align-items: center;
    text-align: center;
    height: 18%;
    margin-bottom: 10px;
    line-height: 100%;
}
.operation>button {
    width: 90% ;
    height: 100%;
}